1. Field of the Invention
The present invention relates to a loudspeaker, and, more particularly, to a loudspeaker which is capable of reducing sway of the voice coil during moving axially so as to enhance quality of the sound output.
2. Description of Related Art
The traditional loudspeaker provides a cylindrical voice coil which moves axially in the magnetic clearance and drives the diaphragm to vibrate and output sound. For instance, the loudspeaker disclosed in U.S. Application Publication No. 20120002836 includes a movable diaphragm, a resilient centering device for centering and guiding the movement of the diaphragm, and a magnet system for controlling the movement of the diaphragm, wherein the diaphragm is positioned between the magnet system and the resilient centering device.
A loudspeaker disclosed in Taiwan Utility Model No. M264793 includes a cone-shaped frame which is integrally formed with a column; the column with an axial through hole faces the opening of the cone; a front piece, a magnet, and a yoke are mounted on the column with a fixing element; the column is surrounded with a centering device and a voice coil; a diaphragm is disposed between the voice coil and the frame.
The fixing element recited in the preceding Taiwan Utility Model has to provide a length enough for extending to the front end of the yoke from the bottom of the frame; when the diaphragm vibrates and emits sounds, the front end of the yoke sways with a large offset to result in the voice coil deviating from the axial movement and distorting the sound output; moreover, it generates noise due to friction cause by the voice coil touching the column or the yoke. In addition, in order to be pierced by the fixing element, the magnet recited in the preceding Taiwan Utility Model No. M264793 provides a through hole, but comparing with the magnet without the through hole, the magnet with the through hole reduces the magnetic performance and degrades quality of the sound output.